Amnesty International has urged authorities in Cote d'Ivoire to protect the population as tens of thousands of people were forced to flee heavy gunfire amid intensified fighting across the country.
Clashes between armed commandos and members of the security forces loyal to outgoing President Laurent Gbagbo have persisted for several days in the city of Abidjan, leaving many dead.
"The humanitarian crisis in Cote d'Ivoire is being exacerbated by the tens of thousands of people fleeing Abidjan who need immediate protection and assistance," said Veronique Aubert, Amnesty International's Africa deputy director.
"Many of those displaced by the fighting, including women and children, are having difficulty finding shelter and some are sleeping in the open air."
Much of the fighting in Abidjan has been between security forces and an armed group calling themselves the "Invisible Commandos", who claim to be fighting independently.
Residents living in the Abobo neighbourhood of the city told Amnesty International that the clashes have left them without water or electricity.
Violence has recently escalated in Cote d'Ivoire in the wake of the disputed presidential election of November 2010. Opposition candidate Alassane Ouattara is the internationally recognized winner of the poll but the outgoing President Gbagbo has refused to step down.
Several people have also been killed by pro-Gbagbo groups known as The Young Patriots. On Sunday, members of this group burned alive a man they suspected to be a rebel in the neighbourhood of Yopougon.
An eyewitness told Amnesty International: "A stranger who was asking for directions was arrested by some Young Patriots. He couldn't speak French and was not able to make himself understood. They took him to a little alley, put a tyre around his neck and set it ablaze."
Another resident said: "As soon as someone is not known in the neighbourhood, the Young Patriots consider him a rebel."
"These incidents show that the population is left without any effective protection - anyone can be targeted by either side," said Veronique Aubert.
Abobo residents told Amnesty International the dire situation had forced them out of the neighbourhood.
"We are fleeing because every night we hear exchange of fire and because there has been no water or electricity in our neighbourhood for two days - the shops are closed, there is nothing to eat" one local said today.
Another fleeing resident told Amnesty International: "The bodies of people killed are still lying on the ground. No one is picking them up and we fear a spread of illnesses due to the decomposing bodies."
Charles Ble Goude, the Youth Minister appointed by Laurent Gbagbo and leader of the Young Patriots, last week called on people to block UN peacekeepers from moving around country, raising the prospect of clashes between civilians and UN troops.
The UN mission has been targeted and said that that three peacekeepers were wounded on Sunday when they were shot at while patrolling Abobo, accusing supporters of Gbagbo of carrying out an ambush.
Yesterday, the UN reported that two UN personnel were abducted and held for several hours by Young Patriots in Abidjan.
In the past week the fighting has extended to other parts of the country.
In the west, clashes between the New Forces - who control the north and part of the west of the country - and pro-Gbagbo forces have forced thousands of people to flee their homes, some to neighbouring Liberia.
Yamoussoukro, the political capital, has also been hit by clashes between security forces loyal to Gbagbo and pro-Ouattara youth.